Surgical repair of tendons and ligaments, and particularly flexor tendons, has been accurately described as a "technique-intensive surgical undertaking." The repair must be of sufficient strength to prevent gapping at the opposed end faces of the repaired member and to permit post-repair application of rehabilitating manipulation of the tendon or ligament.
Considerable effort has been directed toward the development of various suturing techniques to repair severed or ruptured tendons and ligaments. The technique which is probably in most widespread use is by repair of the tendons using various suture techniques. The most common suture technique is known as the Kessler repair, which involves the use of sutures that span in a particular configuration or pattern across the opposed severed ends of the tendon or ligament. There are, however, a wide variety of suturing patterns which have been developed in an effort to attempt to increase the tensile strength across the surgical repair during the healing process. Evans and Thompson in an article entitled "The Application of Force to the Healing Tendon" in the Journal of Hand Therapy, October-December, 1993, pages 266-282 survey the various suturing techniques which have been employed in surgical tendon repair, and in two articles by Strickland in the Journal of American Academy of Orthopaedic Surgeons entitled "Flexor Tendon Injuries: I. Foundations of Treatment" and "Flexor Tendon Injuries: II. Operative Technique", Volume 3, No. 1, January/February, 1995, pages 44-62, the various techniques also are described and illustrated.
Generally, the tensile force at which a tendon repair joint will fail increases with increased complexity of the suturing scheme. As can be seen from the Evans and Thompson article, the loads which failure occur across a sutured joint can vary between about 1,000 grams to reported failures as high as about 8,000 grams. The Kessler and modified Kessler techniques are relatively simple in their suturing pattern, but they tend to have a failure strength toward the low end of the range, for example, between about 1,500 to 4,000 grams.
As is reported in Evans and Thompson, at least one researcher has employed a Mersilene mesh sleeve having a size slightly larger than the tendon that is sutured to the opposed tendon ends. Using the sleeve experimental failure loading as high as 10,000 grams was reported. Mersilene, which is the material that sutures are often made of, has the disadvantage that human tissue will adhere or experience adhesion to the Mersilene. This is undesirable in flexor tendons and ligaments since the tendon must be able to glide relative to the surrounding tissue during the flexing process. Moreover, a sleeve may be well suited for use with tendons and ligaments which are substantially cylindrical, but it becomes less easily employed with tendons having a flat or ovaloid cross section.
In an article by Mitsuhiro, et al. in The Journal of Hand Surgery, Vol. 19A, No. 6, November, 1994, pp 984-990, entitled "Tendon Repair Using Flexor Tendon Splints: An Experimental Study" techniques are described for surgically repairing tendons using a tendon splint. In one approach the opposed tendon ends are slit and the splint, a generally rectangular Dacron member, spans across and is positioned in each slit tendon end. This internally positioned splint is then sutured in place across the tendon ends using various suturing patterns. In another approach described in the Mitsuhiro, et al. article, the rectangular splint is sutured to the back side of the tendons across the severed ends. As noted by Mitsuhiro, et al., both these techniques have disadvantages. The positioning of a splint internally by slitting the tendon ends may damage tendon blood supply, and the external positioning of a Dacron splint can interfere with tendon gliding.
Accordingly, development of surgical tendon and ligament repair techniques that are less technique-intensive and yet have a high strength across the repaired joint is a highly desirable goal. Such repair techniques should minimize the adhesion potential and permit member excursions during manipulation to effect rehabilitation.
It is an object of the present invention, therefore, to provide a tendon or ligament splint which can be used to splint together opposed ends of the tendon or ligament in a relatively simple procedure to provide enhanced joint strength.
A further object of the present invention is to provide a tendon or ligament splint and method which have improved compatibility with the body and are suitable for joining flexor tendons and ligaments, which normally must experience substantial longitudinal excursions without adhesion to surrounding tissue.
Still another object of the present invention is to provide a surgical method of repairing or joining together opposed tendon or ligament ends which is less tedious and time-consuming and yet provides a high-strength, body-compatible tendon joint.
The surgical tendon or ligament splint and method of the present invention have other objects and features of advantage which will become apparent from, and are set forth in more detail in, the accompanying drawing and following description of the Best Mode of Carrying Out The Invention.